linux.git/arch/powerpc/kernel/vdso32, branch v5.4.249

powerpc: Fix vDSO clock_getres()

2019-12-17T18:56:47+00:00

[ Upstream commit 552263456215ada7ee8700ce022d12b0cffe4802 ]

clock_getres in the vDSO library has to preserve the same behaviour
of posix_get_hrtimer_res().

In particular, posix_get_hrtimer_res() does:
    sec = 0;
    ns = hrtimer_resolution;
and hrtimer_resolution depends on the enablement of the high
resolution timers that can happen either at compile or at run time.

Fix the powerpc vdso implementation of clock_getres keeping a copy of
hrtimer_resolution in vdso data and using that directly.

Fixes: a7f290dad32e ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel")
Cc: stable@vger.kernel.org
Signed-off-by: Vincenzo Frascino 
Reviewed-by: Christophe Leroy 
Acked-by: Shuah Khan 
[chleroy: changed CLOCK_REALTIME_RES to CLOCK_HRTIMER_RES]
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/a55eca3a5e85233838c2349783bcb5164dae1d09.1575273217.git.christophe.leroy@c-s.fr
Signed-off-by: Sasha Levin

powerpc/32s: drop CPU_FTR_USE_RTC feature

2019-08-28T13:19:33+00:00

CPU_FTR_USE_RTC feature only applies to powerpc601.

Drop this feature and replace it with tests on CONFIG_PPC_BOOK3S_601.

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/170411e2360861f4a95c21faad43519a08bc4040.1566834712.git.christophe.leroy@c-s.fr

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Reviewed-by: Richard Fontana 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman

powerpc/vdso: Drop unnecessary cc-ldoption

2019-05-01T00:49:58+00:00

Towards the goal of removing cc-ldoption, it seems that --hash-style=
was added to binutils 2.17.50.0.2 in 2006. The minimal required
version of binutils for the kernel according to
Documentation/process/changes.rst is 2.20.

Suggested-by: Masahiro Yamada 
Signed-off-by: Nick Desaulniers 
Reviewed-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman

powerpc/vdso32: fix CLOCK_MONOTONIC on PPC64

2019-04-07T20:57:19+00:00

Commit b5b4453e7912 ("powerpc/vdso64: Fix CLOCK_MONOTONIC
inconsistencies across Y2038") changed the type of wtom_clock_sec
to s64 on PPC64. Therefore, VDSO32 needs to read it with a 4 bytes
shift in order to retrieve the lower part of it.

Fixes: b5b4453e7912 ("powerpc/vdso64: Fix CLOCK_MONOTONIC inconsistencies across Y2038")
Reported-by: Christian Zigotzky 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman

powerpc: Enable kcov

2019-02-23T10:04:32+00:00

kcov provides kernel coverage data that's useful for fuzzing tools like
syzkaller.

Wire up kcov support on powerpc. Disable kcov instrumentation on the same
files where we currently disable gcov and UBSan instrumentation, plus some
additional exclusions which appear necessary to boot on book3e machines.

Signed-off-by: Andrew Donnellan 
Acked-by: Dmitry Vyukov 
Tested-by: Daniel Axtens  # e6500
Signed-off-by: Michael Ellerman

powerpc/vdso: Correct call frame information

2018-09-14T03:47:31+00:00

Call Frame Information is used by gdb for back-traces and inserting
breakpoints on function return for the "finish" command.  This failed
when inside __kernel_clock_gettime.  More concerning than difficulty
debugging is that CFI is also used by stack frame unwinding code to
implement exceptions.  If you have an app that needs to handle
asynchronous exceptions for some reason, and you are unlucky enough to
get one inside the VDSO time functions, your app will crash.

What's wrong:  There is control flow in __kernel_clock_gettime that
reaches label 99 without saving lr in r12.  CFI info however is
interpreted by the unwinder without reference to control flow: It's a
simple matter of "Execute all the CFI opcodes up to the current
address".  That means the unwinder thinks r12 contains the return
address at label 99.  Disabuse it of that notion by resetting CFI for
the return address at label 99.

Note that the ".cfi_restore lr" could have gone anywhere from the
"mtlr r12" a few instructions earlier to the instruction at label 99.
I put the CFI as late as possible, because in general that's best
practice (and if possible grouped with other CFI in order to reduce
the number of CFI opcodes executed when unwinding).  Using r12 as the
return address is perfectly fine after the "mtlr r12" since r12 on
that code path still contains the return address.

__get_datapage also has a CFI error.  That function temporarily saves
lr in r0, and reflects that fact with ".cfi_register lr,r0".  A later
use of r0 means the CFI at that point isn't correct, as r0 no longer
contains the return address.  Fix that too.

Signed-off-by: Alan Modra 
Tested-by: Reza Arbab 
Signed-off-by: Paul Mackerras

powerpc: Add build salt to the vDSO

2018-07-17T16:18:05+00:00

The vDSO needs to have a unique build id in a similar manner
to the kernel and modules. Use the build salt macro.

Signed-off-by: Laura Abbott 
Signed-off-by: Masahiro Yamada

powerpc/kbuild: Remove CROSS32 defines from top level powerpc Makefile

2018-06-01T13:08:06+00:00

Switch VDSO32 build over to use CROSS32_COMPILE directly, and have
it pass in -m32 after the standard c_flags. This allows endianness
overrides to be removed and the endian and bitness flags moved into
standard flags variables.

Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman